Timmermans hails from the continent's centre-left - he's a Dutch social democrat. The 58-year-old is a member of the country's Labour party (PvdA), for whom he served as foreign minister until 2014, when he went to Brussels to become a Commissioner.
A student of French literature and European law, Timmermans attended an English school in Rome: his international upbringing has left him with a command of at least six languages, including English, French, German, Italian, and apparently Russian.
Timmermans is a noted Anglophile: in 2016 he revealed that he owned a car - a British Mini - with a union jack painted on the roof.
"Recently my family bought a car. Its concept is quintessentially British, it oozes 'Cool Britannia'," he said at the time.
"We chose the roof with the Union Jack. As a tribute to the people who came up with the idea of the original Mini, the coolest car of my childhood."
The commissioner added that for his father's generation the union flag represented the liberation of the Nazi-occupied Netherlands during the Second World War.
Also of note for Brits, Timmermans supports a second referendum on Brexit: in April this year he told the UK to "cool down" and decide to stay in.
“I absolutely hope that the UK might stay in the EU," he said during the run-up to the European parliament elections.
“I hope this period of extension will be used for Britain to calm down and rethink things a bit, perhaps for politicians to be more responsible with the promises they make, and then look at the issue again later this year. Who knows what might change in the meantime?"
He could have a rocky relationship with the man set to be the UK's prime minister, though: he's previously criticised Boris Johnson by name for making "borderline racist" comments.
If Timmermans is appointed he would be the first Commission president not from the centre-right since Romano Prodi, who took office in 1999.
Timmermans is from a Catholic family in Maastricht – the city that one of the EU's founding treaties was named after. He stood on a manifesto at the EU elections that attacked the "dangerous delusions" of nationalists and promised a "change of leadership and policy direction, leaving behind the neoliberal and conservative models of the past".
He could be more radical than his predecessor: he's talked about policies such as an EU-wide regulation of minimum wages. In office he's led the charge at the Commission against far-right regimes taking hold in the bloc's eastern countries. But he's also been first vice president since 2014 - effectively Juncker's deputy. How much will he really change? It's hard to say until he's been given a chance.
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